view src/share/vm/runtime/monitorChunk.hpp @ 3979:4dfb2df418f2

6484982: G1: process references during evacuation pauses Summary: G1 now uses two reference processors - one is used by concurrent marking and the other is used by STW GCs (both full and incremental evacuation pauses). In an evacuation pause, the reference processor is embedded into the closures used to scan objects. Doing so causes causes reference objects to be 'discovered' by the reference processor. At the end of the evacuation pause, these discovered reference objects are processed - preserving (and copying) referent objects (and their reachable graphs) as appropriate. Reviewed-by: ysr, jwilhelm, brutisso, stefank, tonyp
author johnc
date Thu, 22 Sep 2011 10:57:37 -0700
parents f95d63e2154a
children d2a62e0f25eb
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/*
 * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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#ifndef SHARE_VM_RUNTIME_MONITORCHUNK_HPP
#define SHARE_VM_RUNTIME_MONITORCHUNK_HPP

#include "runtime/synchronizer.hpp"

// Data structure for holding monitors for one activation during
// deoptimization.

class MonitorChunk: public CHeapObj {
 private:
  int              _number_of_monitors;
  BasicObjectLock* _monitors;
  BasicObjectLock* monitors() const { return _monitors; }
  MonitorChunk*    _next;
 public:
  // Constructor
  MonitorChunk(int number_on_monitors);
  ~MonitorChunk();

  // link operations
  MonitorChunk* next() const                { return _next; }
  void set_next(MonitorChunk* next)         { _next = next; }

  // Tells whether the monitor chunk is linked into the JavaThread
  bool is_linked() const                    { return next() != NULL; }

  // Returns the number of monitors
  int number_of_monitors() const { return _number_of_monitors; }

  // Returns the index'th monitor
  BasicObjectLock* at(int index)            { assert(index >= 0 && index < number_of_monitors(), "out of bounds check"); return &monitors()[index]; }


  // Memory management
  void oops_do(OopClosure* f);

  // Tells whether the addr point into the monitors.
  bool contains(void* addr) const           { return (addr >= (void*) monitors()) && (addr <  (void*) (monitors() + number_of_monitors())); }
};

#endif // SHARE_VM_RUNTIME_MONITORCHUNK_HPP